Preheat the oven to 200°C. Place the crushed Bakers Snacktime biscuits, cream cheese, cheddar, onion bits and chives into a mixing bowl, season well, then mix all the ingredients until well combined. Place the mushrooms onto a lined baking tray with the hollow side facing upwards. Scoop the cheese and biscuit filling into each mushroom, then place them in the oven for 25-30 minutes, until golden. Allow the mushrooms to rest for 2-3 minutes before serving them alongside your festive roasts.